To increase density of the information stored on a magnetic storage media, one has to reduce the spatial distribution of the magnetic field generated by a write element in a recording head. With the conventional magnetic recording approach, one has to rely on the continuous reduction of the write element lateral dimensions; reduction of the head-to-media spacing (HMS); and/or reduction of the media grain size.
This strategy has its fundamental limitations. For example, it leads to a reduction of the write field amplitude and increasing fabrication expenses. It also leads to more complicated overcoat and lubrication solutions.
Thermally assisted magnetic recording (also referred to as heat assisted magnetic recording (HAMR)) has been developed to address instabilities that result from a reduction in grain size. HAMR generally refers to the concept of locally heating a recording medium to reduce the coercivity of the recording medium so that an applied magnetic writing field can more easily direct the magnetization of the recording medium during the temporary magnetic softening of the recording medium caused by the heat source. Heat assisted magnetic recording allows for the use of small grain media, which is desirable for recording at increased areal densities, with a larger magnetic anisotropy at room temperature to assure sufficient thermal stability.
In thermally assisted magnetic recording, information bits are recorded on a storage layer at elevated temperatures, and the heated area in the storage layer determines the data bit dimension. In one approach, a beam of light is condensed to a small optical spot onto the recording media to heat a portion of the media and reduce the magnetic coercivity of the heated portion. Data is then written to the reduced coercivity region.
However, to achieve additional increases in data storage capacities, there remains a need for further reduction in the size of data bits written in the storage media in magnetic recording systems.